Battery clips to the ear sends electric pulses to it wirelessly

A pea-sized device that produces weak pulses of electricity is being tested as a treatment for migraine.

The StimRelieve Halo system consists of a tiny implant inserted into the forehead, just under the skin, and a battery which clips to the ear and sends electric pulses to it wirelessly.

More than 140 people are taking part in a U.S. trial, where they will have the implant fitted, but half won’t have the batteries activated. Patients can trigger an electric signal using a button on the battery.

Migraines are thought to result from abnormal brain activity, which temporarily affects nerve signals, chemicals and blood vessels, leading to pain. The idea is that the electrical pulses block or interfere with pain signals.